com.google.common.collect.testing

Class MinimalIterable<E>

java.lang.Object

com.google.common.collect.testing.MinimalIterable<E>

All Implemented Interfaces:

java.lang.Iterable<E>

@GwtCompatible
public final class MinimalIterable<E>
extends java.lang.Object
implements java.lang.Iterable<E>

An implementation of Iterable which throws an exception on all invocations of the iterator() method after the first, and whose iterator is always unmodifiable.

The Iterable specification does not make it absolutely clear what should happen on a second invocation, so implementors have made various choices, including:

• returning the same iterator again
• throwing an exception of some kind
• or the usual, robust behavior, which all known Collection implementations have, of returning a new, independent iterator

Because of this situation, any public method accepting an iterable should invoke the iterator method only once, and should be tested using this class. Exceptions to this rule should be clearly documented.

Note that although your APIs should be liberal in what they accept, your methods which return iterables should make every attempt to return ones of the robust variety.

This testing utility is not thread-safe.

Author:

Kevin Bourrillion

Method Summary

Modifier and Type	Method and Description
static <E> MinimalIterable<E>	from(java.util.Collection<E> elements) Returns an iterable whose iterator returns the given elements in order.
java.util.Iterator<E>	iterator()
static <E> MinimalIterable<E>	of(E... elements) Returns an iterable whose iterator returns the given elements in order.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Method Detail

of

public static <E> MinimalIterable<E> of(E... elements)

Returns an iterable whose iterator returns the given elements in order.

from

public static <E> MinimalIterable<E> from(java.util.Collection<E> elements)

Returns an iterable whose iterator returns the given elements in order. The elements are copied out of the source collection at the time this method is called.

iterator

public java.util.Iterator<E> iterator()

Specified by:

iterator in interface java.lang.Iterable<E>